I'm new to blender and having a lot of trouble simulating because of bad subdivisions (importing my objects from rhino as OBJs)
The subdivision surface modifier is optimized for meshes that are entirely (for the most part) constructed of quads. Your CAD imports have a lot of uneven topology and tris. This is inevitable when you are working in CAD programs with NURBS and then are forced to convert them to polygons so you can open in Blender (or other mesh based modeling tools). It's why you are getting ugly results with the subsurf modifier.
Here is how cloth simulation works &quot;under the hood&quot; (Straight from the blender docs):

As you can see from the above, accurate simulations depend on even topology so it can compute springs properly.
Unfortunately there is no magic button or export option that will fix your problem. Blender can't natively import NURBS - at some point in the pipeline you are converting from parametric data to polygons and horrible topology is inevitable.
The closest thing to an &quot;easy fix&quot; would be to import your model into ZBrush, and use ZRemesher.
Beyond that, your only other option is to remodel/retopologize the cloth you want to simulate using traditional subd modeling techniques.
Hope this helps.